I have a Patick Green Deb's Deluxe.
One of the most important things to look for, in my opinion, is the TPI (teeth per inch). Geth the highest TPI you can afford.
Fine fibers need a lot of teeth per inch to card smoothly. The lower TPI are used for medium to coarse fiber. You can always card medium to coarse fiber on a high TPI count, but it is hard to get a smooth batt of fine fiber on a low TPI count.
eta: Went to my 'go to' fiber equipment supplier (Susan's Fiber shop). She has the new Ashford Wild Card for $380. It has 128 TPI (a 'fine' carder). Susan recommends it and she has never steered me wrong!